Deflavored vegetable powders, methods of making them, and systems for vegetable milling

ABSTRACT

The present invention relates to vegetable powders and methods of making them. The methods can include one or more inventive methods of dehulling, steaming, and/or milling and air classifying a millable vegetable. The vegetable powders can have improved processing characteristics, enhanced nutritional value, and/or improved flavor compared to conventional vegetable powders.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation of U.S. application Ser. No. 10/718,186, filedNov. 19, 2003, which application is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to vegetable powders, methods of makingthem, and systems for vegetable milling. The vegetable powders can haveimproved processing characteristics, enhanced nutritional value, and/orimproved flavor compared to conventional vegetable powders. The methodscan include one or more inventive methods of dehulling, steaming, and/ormilling and air classifying a millable vegetable. The systems forvegetable milling can include an inventive configuration of steaming,milling, and classifying apparatus together with air handling systems.

BACKGROUND OF THE INVENTION

Vegetable powders are produced using a variety of known methods and areused as a base for many food products. While existing vegetable powdersare used to create many different food products, most of them have anoff odor and taste, chalky feel, and low protein content due to themethod used to make the powder.

Soymilk, for example, has great potential, but has yet to catch on inthe west. Soymilk is lactose and cholesterol free, nutritious, andhealthful. It has traditionally been a staple of the Chinese diet. Inthe United States, soymilk has not been well received. Soymilk istraditionally made by soaking soybeans, grinding them with water,cooking the slurry, filtering the slurry to remove the sludge, and thenheating the extract. This process results in a beverage that has anoff-flavor and odor which many cultures simply do not accept.

To make soymilk more appealing to consumers, its processing anddeflavoring has been a topic of research in the United States fordecades. Many researchers have been left frustrated trying tosufficiently reduce the off-flavor and odor and chalkiness ofconventional soymilk. Several researchers have attempted to develop apowdered soy beverage adaptable to the tastes of diverse cultures, butmany of these resulted in a soymilk with a low protein content and abland, chalky taste. For example, bad flavor can be reduced by boilingsoybeans, and this is exploited in the “Illinois” method. However,boiled beans still yield a product with bad mouth feel, chalkiness,and/or low protein content.

There remains a need for a vegetable powder that has or can makeproducts with commercially acceptable flavor, mouth feel, and/or proteincontent.

SUMMARY OF THE INVENTION

The present invention relates to vegetable powders, methods of makingthem, and systems for vegetable milling. The vegetable powders can haveimproved processing characteristics, enhanced nutritional value, and/orimproved flavor compared to conventional vegetable powders. The methodscan include one or more inventive methods of dehulling, steaming, and/ormilling and air classifying a millable vegetable. The systems forvegetable milling can include an inventive configuration of steaming,milling, and classifying apparatus together with air handling systems.

The present invention includes a vegetable powder. The vegetable powdercan be composed of particles, at least about 80% of the particles canhave a size below about 10 to about 30 μm. The vegetable powder can havea mean particle size of about 10 μm.

The vegetable powder can yield an aqueous homogenate that has flavorrank indicating flavor superior to that of conventional vegetablepowders. For example, the vegetable powder can have a flavor rankindicating a good, nutty, pleasant soy flavor, which can correspond to anumerical rank of about 8.5 or more. This rank can be based on flavorscale on which the lowest rank (1) indicates green beany flavor and thehighest rank (10) indicates fresh and pleasant flavor.

The vegetable powder can yield an aqueous homogenate that has off tasterank indicating flavor superior to that of conventional vegetablepowders. For example, the vegetable powder can have a off taste rankindicating off taste of slightly oxidized, slight cardboard, or somewhatgreen off taste, which can correspond to a numerical rank of about 3 orlower. This rank can be based on an off taste scale on which the lowestrank (1) indicates the lowest amount of off taste and no rancid tasteand the highest rank (10) indicates the highest amount of off taste andmaximum rancidity.

The present method can include a method of producing vegetable powder.The method can include contacting millable vegetable with steam at about95° C. to about 130° C. for about 3 to about 12 min, milling themillable vegetable, and producing vegetable powder of which 70% has aparticle size less than 20 microns. The method can include millingmillable vegetable with milling including contacting the vegetable withair previously passed through a cooling apparatus during milling,contacting the vegetable with air previously passed through a dryingapparatus during milling, or a combination thereof.

The method can include milling millable vegetable and simultaneouslywith milling, classifying the milled vegetable. The classifying caninclude contacting the vegetable with air previously passed through acooling apparatus during classifying, contacting the vegetable with airfrom a drying apparatus during classifying, or a combination thereof.

The method can include dehulling the millable vegetable. The dehullingcan include dehulling vegetable having a mixture of sizes, gently dryingthe vegetable and dehulling the gently dried vegetable, dehulling atambient temperature, or a combination thereof.

The present system can include a system for producing vegetable powder.The system can include steaming apparatus, milling apparatus,classifying apparatus, air cooling apparatus, and air drying apparatus.The system can also include vegetable handling apparatus and/or airhandling apparatus. The air handling apparatus can be configured totransport the air from the cooling apparatus and/or drying apparatus tothe milling apparatus, to the vegetable handling apparatus between themilling apparatus and the classifying apparatus, and/or to theclassifying apparatus.

BRIEF DESCRIPTION OF THE FIGURE

FIG. 1 schematically illustrates an embodiment of the method of thepresent invention including steaming, milling, and/or classifying.

FIG. 2 schematically illustrates an embodiment of a system for carryingout steaming, milling, and/or classifying according to an embodiment ofthe present invention.

FIG. 3 schematically illustrates a second embodiment of a system forcarrying out steaming, milling, and/or classifying according to anembodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Definitions

As used herein, “millable vegetable” refers to any vegetable that can bemilled into a powder and that can benefit from a deflavoring treatment,and to parts of these vegetables. Millable vegetables include legumes(e.g., oleaginous and non-oleaginous legumes), grains (e.g., cerealgrains), seeds of these millable vegetables, and the like. Legumesinclude black beans, pinto beans, red beans, broad beans, lentils,soybeans (e.g., whole soybeans, soybean germ, or soybean cotyledon),navy beans, and peas.

As used herein, “deflavoring” refers to reducing or removingobjectionable flavor notes characteristic of millable vegetables, suchas soybeans.

As used herein, the term “about” modifying the quantity of an ingredientin the compositions of the invention or employed in the methods of theinvention refers to variation in the numerical quantity that can occur,for example, through typical processing and measuring procedures usedfor making and evaluating vegetable powders in the real world; throughinadvertent error in these procedures; through differences in themanufacture, source, or purity of the ingredients or apparatus employedto make the powders or carry out the methods; and the like. Whether ornot modified by the term “about”, the claims include equivalents to thequantities.

Vegetable Powder

The present invention relates to an improved vegetable powder, e.g., apowdered millable vegetable. Compared to conventional vegetable powders,such a vegetable powder can have one or more of improved processingcharacteristics, enhanced nutritional value, and/or improved flavor. Incertain embodiments, the present vegetable powder has one or more ofimproved flavor, reduced off-taste and/or off-smell, and improved mouthfeel. Such vegetable powders can be produced by the present method.

In an embodiment, the present vegetable powder or product containing ormade from the present vegetable powder can have flavor rated better thanthe flavor of conventional vegetable powders and products made from theconventional powders. Flavor can be evaluated by any of a variety ofknown methods. For example, the present vegetable powder or product madefrom it can be evaluated for flavor by a flavor panel according to astandard scale of flavor.

In an embodiment, flavor can be evaluated by producing an aqueoussuspension or homogenate of the vegetable powder and ranking the flavorof the suspension or homogenate on a flavor scale. Such a scale can, forexample, rank soybean (e.g., soy powder or soy milk) flavors from 1 to10 with, for example, 1 being the lowest rank and indicating a rancidflavor; a rank of 2 indicating a painty flavor; a rank of 3 indicating arancid and sour flavor; a rank of 4 indicating a soapy flavor; a rank of5 indicating an obviously green and beany flavor, an unpleasant soyflavor; a rank of 6 indicating little beany flavor, flat soy flavor; arank of 7 indicating a slightly beany flavor and little nutty flavor; arank of 8 indicating good, nutty, clean soymilk flavor; a rank of 9indicating a bland flavor; and 10 being the highest rank and indicatinga fresh and pleasant flavor. A conventional vegetable powder can yield asuspension or homogenate with a flavor ranking below 5. A vegetablepowder according to the present invention yields a suspension orhomogenate with a flavor ranking of at least 7, at least 8, at least8.5, or at least 9.

In an embodiment, the present vegetable powder or product containing ormade from the present vegetable powder can have reduced off tastecompared to conventional vegetable powders and products made from theconventional powders. Off taste can be evaluated by any of a variety ofknown methods. For example, the present vegetable powder or product madefrom it can be evaluated for off taste by a flavor panel according to astandard scale of off taste.

In an embodiment, off taste can be evaluated by producing an aqueoussuspension or homogenate of the vegetable powder and ranking the offtaste of the suspension or homogenate on a scale. Such a scale can, forexample, rank soybean (e.g., soy powder or soy milk) off tastes from 1to 10 with 1 indicating the lowest amount of off taste, e.g., no rancidtaste, and 10 indicating the highest amount of off taste, e.g., maximumrancidity. According to this scale, rank and off taste correspond as: 1,no rancid taste; 2, slightly bitter off taste; 3, slightly oxidized,slight cardboard, or somewhat green off taste; 4, slightly cooked offtaste; 5, metallic off taste; 6, beany off taste; 8, soapy off taste; 9,painty off taste; and 10, very rancid off taste. A vegetable powderaccording to the present invention yields a suspension or homogenatewith a off taste ranking of less than or equal to 4, less than or equalto 2, or less than or equal to 1.

In an embodiment, the present vegetable powder or product containing ormade from the present vegetable powder can have color rated better thanthe color of conventional vegetable powders and products made from theconventional powders. Color can be evaluated by any of a variety ofknown methods. For example, the present vegetable powder or product madefrom it can be evaluated for color by a color panel according to astandard scale of color.

In an embodiment, the present vegetable powder has advantageously smallsize. For example, the present vegetable powder can have a mean particlesize of about 5 to about 15 μm, about 10 to about 15 μm, or about 8 toabout 15 μm, or about 10 μm. In an embodiment, the present vegetablepowder includes at least about 70% particles of size below about 20 μm.In an embodiment, the present vegetable powder includes at least about80% particles of size below about 20 μm. In an embodiment, the presentvegetable powder includes at least about 90% particles of size belowabout 20 μm. In certain embodiments, the present vegetable powderincludes at least about 80% particles of size below about 20 μm, lessthan about 15 μm, or less than about 10 μm. In an embodiment, thepresent vegetable powder includes at least about 95% particles of sizebelow about 20 to about 25 μm.

In an embodiment, the small size of the present vegetable powder can bedescribed with reference to the mouth feel or astringency of the powder.For example, the present vegetable powder can be of a size such thatconsumers perceive it to lack a gritty texture. For example, the presentvegetable powder can be of a size such that consumers perceive it tolack astringency or mouth drying. Such advantageous characteristics canbe achieved with a powder including at least about 70% particles of sizebelow about 20 μm. In an embodiment, these advantageous characteristicscan be achieved with a powder including at least about 80% particles ofsize below about 20 μm.

In an embodiment, the present vegetable powder or product containing ormade from the present vegetable powder can have enhanced nutritionalvalue compared to conventional vegetable powders and products made fromthe conventional powders. Nutritional value can be evaluated by any of avariety of known methods. Nutritional value can be reflected inmeasurements such as protein dispersiblity, trypsin inhibitor levels,and the like.

For example, nutritional value of the present vegetable powder orproduct made from it can be evaluated by determining the level oftrypsin inhibitor. Lower levels of trypsin inhibitor can advantageouslycorrespond to increased nutritional value. In an embodiment, the presentvegetable powder has advantageously low levels of trypsin inhibitor. Forexample, the present vegetable powder can have levels of trypsininhibitor of less than or equal to about 40% that of the raw vegetable,less than or equal to about 50% that of the raw vegetable, or less thanor equal to about 60% that of the raw vegetable. For example, thepresent vegetable powder can have levels of trypsin inhibitor of lessthan or equal to about 2,000 TIU/g (see, e.g., AOCS Ba12-75), less thanor equal to about 20,000 TIU/g, or less than or equal to about 30,000TIU/g that of the raw vegetable.

For example, aspects of the functional value of the present vegetablepowder or product made from it can be evaluated by determining the levelof protein dispersibility. In an embodiment, the present vegetablepowder has advantageously high protein dispersibility. For example, thepresent vegetable powder can have protein dispersibility of greater thanor equal to about 60% that of the raw vegetable, greater than or equalto about 70% that of the raw vegetable, or greater than or equal toabout 80% that of the raw vegetable. Comparison of the proteindispersibility of the raw vegetable and the vegetable powder can beaccomplished by comparing the protein dispersibility index (PDI) foreach sample.

In an embodiment, the present vegetable powder or product containing ormade from the present vegetable powder can have increased shelf lifecompared to conventional vegetable powders and products made from theconventional powders. Shelf life can be evaluated by any of a variety ofknown methods. For example, shelf life of the present vegetable powderor product made from it can be determined by comparisons of the aging orshelf life of samples of vegetable powders made by different methods orfrom different materials. For example, at the end of useful shelf lifethe vegetable powder has undesirable characteristics such as oxidativelipid rancidity, sulfur (e.g., methane thiol or dimethyl trisulfide)flavors, or cardboard, burnt feather, soapy, painty, beany, or greenflavors.

Processing Millable Vegetables

The present invention also relates to an inventive method for producingvegetable powder. This method can include an inventive dehullingprocess, an inventive steaming process, and/or an inventive millingprocess. FIG. 1 schematically illustrates an embodiment of the method ofthe present invention including steaming, milling, and/or classifying.The present method can operate on any of a variety of millablevegetables. In certain embodiments, the present methods and systemsoperate on millable legumes, such as soybean, black bean, pinto bean. Inan embodiment, the present methods and systems operate operates onsoybean.

Providing Millable Vegetable

The present method can include providing raw millable vegetable orproviding millable vegetable that has been prepared for one or more ofdehulling, steaming, or milling. Before operation of the present method,the millable vegetable can be subject to, for example, transporting,receiving, storing, grading, sorting, washing, drying, cleaning, coldexpressing, or other conventional processes that can prepare a millablevegetable for further processing, e.g., dehulling, steaming, or milling.In an embodiment, preparing a millable vegetable for one or more ofdehulling, steaming, or milling can include transporting, receiving,storing, cleaning, sorting, and/or drying the millable vegetable.

For example, the present method can include storing and/or sorting foodgrade millable vegetables before processing, e.g., before dehulling. Inan embodiment, food grade millable vegetable can be subject to one ormore of: storing in a large tank, passing through a magnetic field(e.g., to remove metal objects), and loading into a sorting device(e.g., a gravity table, a color sorter, or the like).

A sorting device such as a gravity table can remove debris and unwantedvegetable matter from the desired millable vegetables. A gravity tablecan sort material by physical properties including density and particlesize, and are used widely in seed conditioning. A gravity table canseparate shriveled and/or broken millable vegetables from intact andusable millable vegetables.

A color sorter can distinguish vegetables by their hue, color intensityand color brightness. For example, color sorters can accurately identifyand remove off-colored soybeans. Thus, a color sorter can remove greentinted immature soybeans and soybeans with an unclean seed coat, withmosaic virus, or with another seed coat disease.

Dehulling Millable Vegetables

In an embodiment, the present method includes an inventive process fordehulling a millable vegetable having a hull. Dehulling can includeremoving the skin (hull) of the millable vegetable from its meat orcotyledon. Dehulling soybeans or another legume can remove the hull anda small amount of germ. Known dehulling apparatus and processes canhalve or quarter the cotyledons or meats (e.g., producing materiallarger than 8 mesh). In an embodiment, dehulling can produce material assmall as 20 mesh. The present methods of dehulling can employ knowndehulling apparatus (e.g., a cracking mill) and known dehulling methods.The present methods of dehulling can also include dehulling vegetablehaving a mixture of sizes, gently drying the vegetable and dehulling thegently dried vegetable, dehulling at ambient temperature, or acombination thereof.

Conventional dehulling typically requires that the vegetable to bedehulled (e.g., soybean) be sorted or restricted to a uniform size. Incontrast, the present method can include dehulling a millable vegetable(e.g., soybeans) having a mixture of sizes. For example, the mixture ofsizes can result from natural variation in a single crop or variety ofthe vegetable or from combining vegetable from several crops orvarieties. The present method need not include sorting the millablevegetable by size before dehulling. That is, the present method caninclude dehulling millable vegetable (e.g., soybeans) of mixed or allnaturally occurring sizes. For example, the present method can includedehulling beans with sizes greater than or equal to 9/64 inch, greaterthan 13/64 inch, greater than 15/64 inch, from 9/64 inch to greater thanor equal to 20/64 inch, or that include variation in relative size from60% of the mean to greater than or equal to 140% of the mean. Forexample, the present method can include dehulling beans with sizesranging from 10 to 20 64^(th) of an inch. As used herein, the phrase“dehulling a millable vegetable (e.g., soybeans) having a mixture ofsizes” refers to a process excluding sorting the millable vegetable bysize before dehulling.

In an embodiment, the present method includes gently drying the millablevegetable and dehulling the gently dried millable vegetable. Gentledrying can include, for example, exposing millable vegetable to atemperature of about 20 to about 120° C., about 20 to about 70° C.,about 40 to about 60° C., or about 50° C. Gentle drying can take placefor about 0.25 to about 20 hours, about 1 to about 6 hours, about 2 toabout 3 hours, or for about 2 hours. Gentle drying can employ a suitableconventional drying apparatus. Gentle drying can include, for example,exposing soybeans to a temperature of about 50° C. for about 6 hours ina suitable drying apparatus, such as a fluid bed dryer. In anembodiment, gentle drying can include drying a millable vegetable (e.g.,soybeans) from about 8 to about 20 wt-% moisture to a moisture contentof about 6 to about 10 wt-% (e.g., about 6 to about 8.5 wt-%). Gentledrying can advantageously be conducted at a temperature and for a timethat maintains a desirable proportion of functionality of the vegetableprotein. Gentle drying to a moisture content less than or equal to about13 wt-% can provide advantageous stability against spoilage of themillable vegetable by microorganisms.

Dehulling can require temperatures elevated above room or ambienttemperature. In contrast, the present method can include dehulling atroom or ambient temperature. That is, the present method can includedehulling without heating.

In an embodiment, the present method can include screening the dehulledmillable vegetable. During dehulling some germ can separate from the nibor remainder of the millable vegetable. Screening can recover the germfor subsequent processing in the present method and remove dust from themillable vegetable.

Steaming Millable Vegetables

In an embodiment, the present method includes an inventive process ofsteaming the millable vegetable, e.g., the dehulled millable vegetable.Steaming can be conducted at predetermined temperature and/or forpredetermined time. As used herein, steaming a millable vegetable atpredetermined temperature and/or for predetermined time refers to theamount of time for which the millable vegetable is exposed to steam at aparticular temperature. The millable vegetable need not achieve thepredetermined temperature.

In an embodiment, steaming at a predetermined temperature for apredetermined time can be effective to significantly reduce the “beany”flavor (also referred to as green flavor or sulfur flavor) associatedwith legumes such as beans and peas. In an embodiment, such steamtreatment can effectively remove the beany flavor.

In an embodiment, steam treating significantly reduces lipoxygenaseactivity. For example, in certain embodiments, steam treating can reducelipoxygenase activity to less than or equal to about 75%, less than orequal to about 50%, or less than or equal to about 1% of the level foundbefore steam treating. Although not limiting to the present invention,it is believed that reducing lipoxygenase activity reduces bad flavorsfrom oxidized lipids and/or methanethiol. Although not limiting to thepresent invention, it is believed that reducing lipoxygenase activityincreases shelf life. For example, a vegetable powder with only about 1%of remaining lipoxygenase activity can have a shelf life of about 1year.

In an embodiment, steam treating significantly reduces trypsin inhibitoractivity. For example, in certain embodiments, steam treating can reducetrypsin inhibitor activity to less than or equal to about 50%, less thanor equal to about 35%, or less than or equal to about 3% of the levelfound before steam treating. For example, in certain embodiments, steamtreating can reduce trypsin inhibitor activity to less than about 50,000TIU/g, less than about 40,000 TIU/g, less than about 25,000 TIU/g, orless than about 20,000 TIU/g. Although not limiting to the presentinvention, it is believed that reducing trypsin inhibitor activityimproves the nutritional value of the vegetable powder and productsincluding it.

In an embodiment, steam treating maintains significant levels of proteindispersibility. For example, in certain embodiments, steam treating canmaintain levels of protein dispersibility about 85% or more, about 70%or more, or about 50% or more of the level found before steam treating.Protein dispersibility is reported as a percentage, and the levelsreferred to in this paragraph refer to comparison of the percent proteindispersibility with and without steam treating. Although not limiting tothe present invention, it is believed that maintaining significantlevels of protein dispersibility improves the functional value of thevegetable powder and products including it. For example, increasedprotein dispersibility can lead to advantageous protein gellation inproducts made from the vegetable powder.

In certain embodiments, the present method includes steaming thedehulled millable vegetable at a temperature of about 95° C. to about130° C., about 100 to about 125° C., about 105 to about 120° C., about105 to about 115° C., or about 105 to about 110° C. In certainembodiments, the present method includes steaming the dehulled millablevegetable at a temperature less than 130° C. but greater than 95° C.,greater than about 100° C., greater than about 105° C., or greater thanabout 115° C. In certain embodiments, the present method includessteaming the dehulled millable vegetable at a temperature greater than95° C. but less than about 130° C., less than about 120° C., less thanabout 115° C., or less than about 110° C.

In certain embodiments, the present method includes steaming thedehulled millable vegetable at a temperature of 93° C. to 97° C., of 94°C. to 96° C., or of 95° C. In certain embodiments, the present methodincludes steaming the dehulled millable vegetable at a temperature of103° C. to 107° C., of 104° C. to 106° C., or of 105° C. In certainembodiments, the present method includes steaming the dehulled millablevegetable at a temperature of 105° C. to 109° C., of 106° C. to 108° C.,or of 107° C. In certain embodiments, the present method includessteaming the dehulled millable vegetable at a temperature of 113° C. to117° C., of 114° C. to 116° C., or of 115° C. In certain embodiments,the present method includes steaming the dehulled millable vegetable ata temperature of 118° C. to 121° C., of 119° C. to 121° C., or of 120°C. In certain embodiments, the present method includes steaming thedehulled millable vegetable at a temperature of about 95° C., about 105°C. (e.g., 107° C.), about 115° C., or about 120° C. In certainembodiments, the present method includes steaming the dehulled millablevegetable at a temperature of 95° C., 105° C., 107° C., 115° C., or 120°C.

In certain embodiments, the present method includes steaming thedehulled millable vegetable for a time of about 3 to about 12 min orabout 4 to about 8 min. In certain embodiments, the present methodincludes steaming the dehulled millable vegetable for less than or equalto about 12 min but for at least about 3 min, at least about 4 min, orat least about 8 min. In certain embodiments, the present methodincludes steaming the dehulled millable vegetable for a time of at leastabout 3 min but less than or equal to about 12 min, less than or equalto about 8 min, or less than or equal to about 4 min. In certainembodiments, the present method includes steaming the dehulled millablevegetable for a time of about 3 min, about 4 min, about 8 min, or about12 min. In certain embodiments, the present method includes steaming thedehulled millable vegetable for a time of 3 min, 4 min, 8 min, or 12min.

In certain embodiments, the present method includes steaming thedehulled millable vegetable at a temperature of about 95° C. to about130° C. for a time of about 3 to about 12 min or about 4 to about 8 min.In certain embodiments, the present method includes steaming thedehulled millable vegetable at a temperature of about 100 to about 125°C. for a time of about 3 to about 12 min or about 4 to about 8 min. Incertain embodiments, the present method includes steaming the dehulledmillable vegetable at a temperature of about 105 to about 120° C. for atime of about 3 to about 12 min or about 4 to about 8 min. In certainembodiments, the present method includes steaming the dehulled millablevegetable at a temperature of about 105 to about 115° C. for a time ofabout 3 to about 12 min or about 4 to about 8 min. In certainembodiments, the present method includes steaming the dehulled millablevegetable at a temperature of about 105 to about 110° C. for a time ofabout 3 to about 12 min or about 4 to about 8 min.

For example, steaming soybeans at about 95° C. for about 4 min can yielda soy powder with protein dispersibility index (PDI) of about 85% (e.g.,maintain about 95% of protein dispersibility) and reduce lipoxygenaseactivity to about 50% of its level in unsteamed beans. This soy powderproduces a soy milk with a flavor rank of 5, which can be consideredadequate flavor.

For example, steaming soybeans at about 105 (e.g., 107)° C. for about 4min can yield a soy powder with protein dispersibility index (PDI) ofabout 60-75% (e.g., maintain about 65 to about 80% of proteindispersibility), reduce lipoxygenase activity to about 1% its level inunsteamed beans, and reduce trypsin inhibitor activity by about 50%.This soy powder can be stable for about 1 year and can produce a soymilk with a flavor rank of 8.5, which can be considered very pleasingflavor.

For example, steaming soybeans at about 115° C. for about 4 min canyield a soy powder with protein dispersibility index (PDI) of about40-50% (e.g., maintain about 45 to about 55% of protein dispersibility),reduce lipoxygenase activity to less than about 1% its level inunsteamed beans, and reduce trypsin inhibitor activity to less thanabout 20,000 TIU/g. This soy powder can be stable for more than about 1year. This soy powder can produce a soy milk with a slight cooked noteto the flavor, which can be considered a mild negative. Such soy powdercan be, however, useful and well accepted in baked products.

After steaming, the steamed vegetable can be cooled and/or dried beforefurther processing. Cooling the steamed millable vegetable can reducethe temperature of the millable vegetable to about 10° C. to about 40°C. Cooling can include retaining the steamed millable vegetable in acooling device, such as a cooling table, for about 3 to about 12 min.Steaming can increase the moisture content of the millable vegetablebeyond levels advantageous for milling. Drying can reduce the moisturecontent to a level acceptable for milling. For example, steaming canincrease the moisture of soybean nibs to 11 or 12%. The nibs or gritscan be dried to about 6% moisture in preparation for milling. Thepresent method can also employ other or additional procedures forpreparing the steamed vegetable for further processing.

Milling and Air Classifying the Vegetables

In an embodiment, the present method includes an inventive process ofmilling the millable vegetable, e.g., milling the dehulled and/orsteamed vegetable. Milling vegetables can include grinding the vegetableinto a uniformly sized powder using a machine that rubs grains of thevegetable together under pressure. In an embodiment, the present millingmethod includes contacting the vegetable with air from a coolingapparatus during milling, contacting the vegetable with air from adrying apparatus during milling, classifying the vegetable duringmilling, contacting the vegetable with air from a cooling apparatusduring classifying, contacting the vegetable with air from a dryingapparatus during classifying, or a combination thereof.

In an embodiment, the present method employs milling with cool and/ordried air. For example, the present method can include passing airthrough a cooling apparatus and conveying the air from the coolingapparatus through the milling apparatus. For example, the present methodcan include passing air through a drying apparatus and conveying the airfrom the drying apparatus through the milling apparatus. For example,the present method can include passing air through a cooling apparatus,passing air through a drying apparatus, and conveying the air from thecooling and drying apparatus through the milling apparatus. Air from thecooling and/or drying apparatus can pass through the mill and then tothe classifying apparatus. In an embodiment, upon leaving the mill, themilled vegetable can be contacted with air that has been cooled and/ordried.

The present method can include cooling the air used for milling and/orclassifying. The present method can include passing air through acooling apparatus and conveying the air from the cooling apparatusthrough the milling and/or classifying apparatus. The air can be cooledto a temperature effective to prevent or reduce the level of burnt notes(flavor) in the vegetable powder. This can provide vegetable powder withan advantageously neutral flavor. In certain embodiments, the air can beat a temperature of about 10 to about 70° F., about 10 to about 50° F.,about 10 to about 45 (e.g., 43)° F., about 20 to about 60° F., or about20 to about 45° F. Very cold winter (e.g., about 10° F.) air may be coolenough to be used at its natural temperature for milling and/or airclassifying. Nonetheless, the present method can include passing evenvery cold winter air through the cooling apparatus.

The present method can include drying the air used for milling and/orclassifying. The present method can include passing air through a dryingapparatus and conveying the air from the drying apparatus through themilling and/or classifying apparatus. Passing air through a dryingapparatus can include contacting the air with drying agent or desiccant.The air can be dried to an extent effective to avoid or reduceunacceptable sticking or clumping of the vegetable powder. In certainembodiments, after passing through the drying apparatus, the air can beat a water content of about 10 to about 50 gr/lb.

The present method can include classifying the milled vegetable orvegetable powder during milling. For example, the method can includeobtaining milled vegetable from the mill during milling, classifying theobtained milled vegetable, expelling fully milled vegetable powder fromthe mill and classifier, and returning insufficiently milled vegetableto the mill. The powder expelled from the mill and classifier can be,for example, further processed, packaged for sale, converted to otherfood products, stored, or a combination thereof. The powder expelledfrom the mill and classifier can include powder below a predeterminedparticle size. For example, the classifier can be configured to expelparticles of which 80% have a size less than about 20 μm, less thanabout 15 μm, or less than about 10 μm. The insufficiently milledvegetable returned to the mill can be subjected to additional milling.

In an embodiment, the present method includes air classifying the milledvegetable or vegetable powder during milling. Air classifying includesusing air to separate the smaller particles of milled vegetable from thelarger particles. For example, the method can include obtaining milledvegetable from the mill during milling, air classifying the obtainedmilled vegetable, expelling fully milled vegetable powder from the milland air classifier, and returning insufficiently milled vegetable to themill. In an embodiment, the present method employs air classifying withcool and/or dried air. For example, the present method can includepassing air through a cooling apparatus and conveying the air from thecooling apparatus through the air classifying apparatus. For example,the present method can include passing air through a drying apparatusand conveying the air from the drying apparatus through the airclassifying apparatus. For example, the present method can includepassing air through a cooling apparatus, passing air through a dryingapparatus, and conveying the air from the cooling and drying apparatusthrough the air classifying apparatus. Air from the cooling and/ordrying apparatus can pass through the mill before entering the airclassifier. Air entering the classifier can include air that has passedthrough the mill and air conveyed from the cooling and/or dryingapparatus without first passing through the mill.

The present method can include maintaining the vegetable powder at atemperature of about 10 to about 45 (e.g. 43)° C., about 20 (e.g., 21)to about 45 (e.g. 43)° C., about 20 to about 40 (e.g., 38)° C., or about20 to about 30° C. during milling. The present method can includemaintaining the vegetable powder at a water content of about 3 to about13 wt-%, about 4 to about 10 wt-%, or about 5 to about 7 wt-% duringmilling.

The present method of milling and classifying can produce vegetablepowders with one or more of several advantageous characteristics. Incertain embodiments, the present milling and classifying produce avegetable powder including particles 80% of which have size less thanabout 20 μm, less than about 15 μm, or less than about 10 μm. In anembodiment, the present milling and classifying produce vegetable powderwith an advantageously neutral flavor. In an embodiment, the presentmilling and classifying produce vegetable powder with advantageouslyenhanced nutritional value. Although not limiting to the presentinvention, it is believed that the present milling and air classifyingconditions keep the vegetable material and powder at a sufficiently lowtemperature to avoid burnt flavors or unacceptable levels proteindenaturation.

Any of a variety of known apparatus can be employed to mill thevegetable material and reduce its particle size. Suitable knownapparatus includes, for example, jet mill, pin mill, hammer mill, ballmill, roller mill, impact mill, or vibrational energy mill. In anembodiment, the present method employs milling with an air-swept pinmill. The pin mill can be in a configuration of a stator with threeconcentric rings and a rotor with five pins on the inner ring and 10pins on each sequential outer ring. Millable vegetable can be fed to theinner ring and air can push the material through the several rings. Theair can cool the vegetable material. The air can push the smallervegetable material through the rings more quickly than the largermaterial. In such a configuration of a pin mill, the outer rings hit thevegetable material at higher impact speed than the inner rings.

Any of a variety of known apparatus can be employed for classifying themilled vegetable. In an embodiment, the present method employs an airclassifier. The air classifier can be in a configuration including abottom feed of material. The material can take a path straight upthrough the bottom cone of the classifier and into the bottom of therotor. Smaller material can be swept to, for example, a cyclone. Largermaterial can be returned to the mill. The speed of the rotor and airsweep can be varied to determine the particle size recovered from themill. The air classifier can be configured to sweep away particles ofwhich 80% have a size less than about 20 μm, less than about 15 μm, orless than about 10 μm.

The milled and classified vegetable powder can be collected with any ofa variety of conventional apparatus such as, for example, a cyclone. Forthe present method, cycloning can be conducted using a standard highefficiency cyclone. The vegetable powder can then be prepared fordistribution and/or sale, for example, by storage, packaging, andshipping.

System for Milling Vegetables

The present invention also relates to an inventive system for millingvegetables. The system can produce the present vegetable powder and canbe used for the present method. The present system can include aninventive configuration of steaming apparatus, milling apparatus,classifying apparatus, air cooling apparatus, and air drying apparatus.The present system can operate on any of a variety of millablevegetables.

The present system can include steaming apparatus, milling apparatus,and classifying apparatus together with vegetable handling apparatusconfigured to transport the vegetable from the steaming apparatus to themilling apparatus and from the milling apparatus to the classifyingapparatus. The present system can also include air cooling apparatus andair drying apparatus together with air handling apparatus configured totransport the air from the cooling apparatus and drying apparatus to themilling apparatus, to the vegetable handling apparatus between themilling apparatus and the classifying apparatus, and/or to theclassifying apparatus.

The present system includes a steaming apparatus. The steaming apparatuscan be configured to receive millable vegetable, for example, directlyor indirectly from dehulling apparatus, drying apparatus (e.g., firstdrying apparatus), or screening apparatus. The steaming apparatus can beconfigured to steam the millable vegetable at predetermined temperatureand/or for predetermined time. As used herein, steaming a millablevegetable at predetermined temperature and/or for predetermined timerefers to the amount of time for which the millable vegetable is exposedto steam at a particular temperature. The millable vegetable need notachieve the predetermined temperature. Exposing the millable vegetableto steam can include contacting with steam in a chamber.

In certain embodiments, the steaming apparatus can be configured toexpose the millable vegetable to steam at a temperature of about 95° C.to about 130° C., about 100 to about 125° C., about 105 to about 120°C., about 105 to about 115° C., or about 105 to about 110° C. In certainembodiments, the steaming apparatus can be configured to expose themillable vegetable to steam for about 3 to about 12 min or about 4 toabout 8 min.

The present system includes milling apparatus. The milling apparatus canbe configured to receive millable vegetable, for example, directly orindirectly from the steaming apparatus, a vegetable cooling apparatus,or a drying apparatus (e.g., second drying apparatus). The millingapparatus can be configured to maintain the vegetable powder at atemperature of about 10 to about 45 (e.g. 43)° C., about 20 (e.g., 21)to about 45 (e.g. 43)° C., about 20 to about 40 (e.g., 38)° C., or about20 to about 30° C. during milling. The milling apparatus can beconfigured to maintain the vegetable powder at a water content of about3 to about 13 wt-%, about 4 to about 10 wt-%, or about 5 to about 7 wt-%during milling. The milling apparatus can be configured to produce avegetable powder including particles 80% of which have size less thanabout 20 μm, less than about 15 μm, or less than about 10 μm.

The present system can include any of a variety of known millingapparatus. Suitable known apparatus includes, for example, jet mill, pinmill, hammer mill, ball mill, roller mill, impact mill, or vibrationalenergy mill. In an embodiment, the present system can include anair-swept pin mill. The pin mill can be in a configuration of a statorwith three concentric rings and a rotor with five pins on the inner ringand 10 pins on each sequential outer ring.

The present system includes classifying apparatus. The classifyingapparatus can be configured to receive milled vegetable, for example,directly or indirectly from the milling apparatus. The classifyingapparatus can be configured to sweep away particles of which 80% have asize less than about 20 μm, less than about 15 μm, or less than about 10μm. The classifying apparatus can be configured to return largerparticles to the milling apparatus. The present system can include anyof a variety of known classifying apparatus, such as an air classifier.In an embodiment, the classifying apparatus can be an air classifier.The air classifier can be in a configuration including a bottom feed ofmaterial.

The present system includes air cooling apparatus. The air coolingapparatus can be configured to receive air from the surrounding of thesystem or structure containing the system, e.g., the outdoors. The aircooling apparatus can reduce the temperature of air. The air coolingapparatus can pass through air that is already sufficiently cool. Incertain embodiments, the air cooling apparatus can put out air at atemperature of about 10 to about 70° F., about 10 to about 50° F., about10 to about 45 (e.g., 43)° F., about 20 to about 60° F., or about 20 toabout 45° F. Very cold winter (e.g., about 10° F.) air can be passedthrough the air cooling apparatus without significant or any furthercooling. The present system can include any of a variety of air coolingapparatus. Suitable air cooling apparatus include McQuay Air-CooledScrew Compressor chiller.

The present system includes air drying apparatus. The air coolingapparatus can be configured to receive air from the air coolingapparatus or from the surroundings of the system or structure containingthe system, e.g., the outdoors. The air drying apparatus can reduce themoisture content of air. In an embodiment, the air drying apparatus canput out air at a moisture content of about 10 to about 50 gr/lb. Thepresent system can include any of a variety of air drying apparatus. Theair drying apparatus can include a chamber in which air and drying agentor desiccant are contacted, e.g., by passing air through the desiccantor drying agent. Suitable air drying apparatus can include Des ChampsLaboratories Wringer dehumidification systems.

The present system includes air handling apparatus. The air handlingapparatus can be configured to take the air from the air coolingapparatus and/or the air drying apparatus to other portions of, orapparatus in, the system. For example, the air handling apparatus can beconfigured to transport air from the cooling apparatus and dryingapparatus to the milling apparatus, to the vegetable handling apparatusbetween the milling apparatus and the classifying apparatus, and/or tothe classifying apparatus.

In an embodiment, the air handling apparatus can direct air from the aircooling apparatus and/or air drying apparatus into and/or through themilling apparatus. In an embodiment, the air handling apparatus candirect air from the air cooling apparatus and/or air drying apparatusinto and/or through the classifying apparatus. In an embodiment, the airhandling apparatus can direct the air into and/or through the mill andthen to the classifying apparatus. In an embodiment, the air handlingapparatus can direct air to a point at or just beyond the exit from themill, e.g., into the vegetable handing apparatus just beyond the exitfrom the mill.

The present system can include any of a variety of air handlingapparatus. The air handling apparatus can include ducts, dampers, fans,blowers, butterfly valves, slide gates, venturi valves, and the like inany of a variety of conventional configurations. Suitable air handlingapparatus include a MAC bag house with Twin City fans and blowers.

The present system includes vegetable handling apparatus. The vegetablehandling apparatus can be configured to transport vegetable into,between components of, and out of the system. For example, the vegetablehandling apparatus can be configured to transport the vegetable into thesteaming apparatus, from the steaming apparatus to the millingapparatus, from the milling apparatus to the classifying apparatus, outof the classifying apparatus, a combination thereof, or the like. Thepresent system can include any of a variety of vegetable handlingapparatus. The vegetable handling apparatus can include chutes, augers,ducts, blowers, aeromechanical conveyor belts, elevators, pipes andtubes, and the like in any of a variety of conventional configurations.Suitable vegetable handling apparatus include MHS bucket elevators,Cablevey aeromechanical conveyors.

In certain embodiments, the present system can also include one or moreof vegetable transport apparatus, vegetable storage apparatus, vegetablegrading apparatus, vegetable sorting apparatus, vegetable washingapparatus, vegetable drying apparatus, vegetable cleaning apparatus,vegetable cold expressing apparatus, or other conventional apparatusthat can prepare a millable vegetable for further processing.

In an embodiment, the present system can also include a first dryingapparatus configured to receive millable vegetable and to gently dry it.The first drying apparatus can be configured to expose millablevegetable to a temperature of about 20 to about 120° C., about 20 toabout 70° C., about 40 to about 60° C., or about 50° C. The first dryingapparatus can be configured to retain the millable vegetable for about0.25 to about 20 hours, about 1 to about 6 hours, about 2 to about 3hours, or for about 2 hours. The first drying apparatus can be any of avariety of known drying devices, such as a fluid bed dryer. In anembodiment, the first drying apparatus can be a fluid bed dryer.

In an embodiment, the present system includes dehulling apparatus. In anembodiment, the dehulling apparatus can be configured to receivemillable vegetable from the first drying apparatus. The dehullingapparatus can be configured to dehull at room or ambient temperature.The dehulling apparatus can be any of a variety of known dehullingdevices, such as a cracking mill. In an embodiment, the dehullingapparatus can be a cracking mill.

In an embodiment, the present system can also include a screeningapparatus that can be configured to receive vegetable from the dehullingapparatus. The screening apparatus can be configured to separate dustfrom the germ and the grit or nib of the millable vegetable. The dustcan be disposed of. The germ and grit or nib can be milled. Thescreening apparatus can be any of a variety of known screening devicessuitable for millable vegetables, such as a Kason circular vibrationscreener, Tokuju vibrating screen, Midwestern Industries Gyra-Vibeseparator. In an embodiment, the screening apparatus is configured toreceive millable vegetable from the dehulling apparatus.

The present system includes steaming apparatus. In certain embodiments,the steaming apparatus can be configured to receive millable vegetablefrom the dehulling apparatus or the screening apparatus. Suitablesteaming apparatus are described hereinabove.

In an embodiment, the present system can also include a vegetablecooling apparatus configured to receive steamed millable vegetable andto reduce its temperature. The vegetable cooling apparatus can beconfigured to receive steamed millable vegetable from the steamingapparatus. The vegetable cooling apparatus can be any of a variety ofknown cooling devices, such as a cooling table. In an embodiment, thevegetable cooling apparatus can be a cooling table.

In an embodiment, the present system can also include a second dryingapparatus configured to receive steamed millable vegetable and to reduceits moisture content. The second drying apparatus can be configured toreceive steamed millable vegetable from the steaming apparatus or thecooling apparatus. In an embodiment, the second drying apparatus can beconfigured to receive steamed and cooled millable vegetable from thecooling apparatus. The second drying apparatus can be configured toreduce the moisture content of the millable vegetable to a levelacceptable for milling. For example, the second drying apparatus candecrease the moisture of the steamed millable vegetable (e.g., soybeans)nibs from about 11 or 12% to about 6% moisture in preparation formilling. The second drying apparatus can be any of a variety of knowndrying devices, such as a fluid bed dryer. In an embodiment, the seconddrying apparatus can be a fluid bed dryer.

In an embodiment, the present system can also include an aspiratingsystem configured to remove fine and/or light material (e.g., hull) fromthe millable vegetable. For example, the aspirating system can removehulls and material that can interfere with milling the millablevegetable. The aspirating system can be configured to receive millablevegetable from the second drying apparatus. The aspirating system can bean air aspirator configured to remove hulls and other light materialthat separates from the millable vegetable during drying. The aspiratorcan be configured in multiple (e.g., 4) stages. The aspirating systemcan be an air aspirator such as a 4 stage Kice multiaspirator.

The present system includes milling apparatus. In certain embodiments,the milling apparatus can be configured to receive millable vegetablefrom the steaming apparatus, the vegetable cooling apparatus, or thesecond drying apparatus. Suitable milling apparatus are describedhereinabove.

The present system includes classifying apparatus. In an embodiment, theclassifying apparatus can be configured to receive milled vegetable fromthe milling apparatus. Suitable classifying apparatus are describedhereinabove.

In an embodiment, the present system can include any of a variety ofvegetable powder collection apparatus. For example, the present systemcan include a cyclone, such as a standard high efficiency cyclone. Thecyclone can be configured to receive vegetable powder of a desired sizefrom the classifying apparatus. The present system can also includeadditional vegetable powder processing apparatus, packaging apparatus,storage systems, a combination thereof, or the like.

The present system includes air handling apparatus. Suitable airhandling apparatus are described hereinabove. In certain embodiments,the air handling apparatus can be configured to direct air from the aircooling and/or air drying apparatus into or through one or more of thedehulling apparatus, first drying apparatus, screening apparatus,vegetable cooling apparatus, second drying apparatus, vegetable powdercollection apparatus, or the like.

The present system includes vegetable handling apparatus. Suitablevegetable handling apparatus are described hereinabove. In certainembodiments, the vegetable handling apparatus can be configured totransport vegetable material into, through, out of, or between one ormore of the vegetable transport apparatus, vegetable storage apparatus,vegetable grading apparatus, vegetable sorting apparatus, vegetablewashing apparatus, vegetable drying apparatus, vegetable cleaningapparatus, vegetable cold expressing apparatus, dehulling apparatus,first drying apparatus, screening apparatus, vegetable coolingapparatus, second drying apparatus, vegetable powder collectionapparatus, packaging apparatus, storage system, or the like.

Illustrated Embodiments of the System

FIG. 2 illustrates an embodiment of the present inventive system formilling vegetables. As shown in FIG. 2, the illustrated embodiment,includes steamer 1, mill 3, classifier 5, cooler 7, and dryer 9. Airsystem 11 can be configured to convey air into cooler 7, from cooler 7to dryer 9, and/or from dryer 9 to mill 3, to vegetable transport system13, and/or to classifier 5. Vegetable transport system 13 can beconfigured to convey vegetable material into steamer 1, directly orindirectly from steamer 1 to mill 3, directly or indirectly from mill 3to classifier 5, and/or from classifier 13.

Steamer 1 can be any of a variety of steam chambers suitable forsteaming millable vegetables. For example, steamer 1 can include asealed tank in which millable vegetable is contacted with steam from asource of steam. Millable vegetable can be transported through thesteamer by a belt. Steamer 1 can be configured to contact the millablevegetable with steam of a predetermined temperature for a predeterminedtime. Steamer 1 can be configured to contact millable vegetable withsteam at a temperature of about 95° C. to about 130° C., about 100 toabout 125° C., about 105 to about 120° C., about 105 to about 115° C.,or about 105 to about 110° C. In certain embodiments, steamer 1 can beconfigured to contact millable vegetable with steam for about 3 to about12 min or about 4 to about 8 min.

Mill 3 can be any of a variety of mills suitable for milling millablevegetable. For example, mill 3 can be a jet mill, pin mill, hammer mill,ball mill, roller mill, impact mill, or vibrational energy mill. In anembodiment, the mill 3 is an air-swept pin mill. Mill 3 can be in aconfiguration of a stator with three concentric rings and a rotor withfive pins on the inner ring and 10 pins on each sequential outer ring.In an embodiment, air transport system 11 is configured to convey airinto mill 3, e.g., into the center of an air-swept pin mill.

Classifier 5 can be any of a variety of classifiers suitable forclassifying milled vegetables or other particulate matter. For example,classifier 5 can be an air classifier. Classifier 5 can be configured tosweep away particles of which 80% have a size less than about 20 μm,less than about 15 μm, or less than about 10 μm. Classifier 5 can beconfigured to return larger particles to the milling apparatus.

Cooler 7 can be any of a variety of systems suitable for cooling air forindustrial or food processing uses. For example, cooler 7 can be an aircooled screw compressor chiller. Cooler 7 can be configured to produceair at a temperature of about 10 to about 70° F., about 10 to about 50°F., about 10 to about 45 (e.g., 43)° F., about 20 to about 60° F, orabout 20 about 45° F.

Dryer 9 can include any of a variety of systems suitable for drying airfor industrial or food processing uses. For example, dryer 9 can includecan include a chamber in which air and drying agent or desiccant arecontacted, e.g., by passing air through the desiccant or drying agent inapparatus such as a Des Champs Wringer dehumidification system with awound silica gel desiccant wheel. Dryer 9 can be configured to produceair at a moisture content of about 10 to about 50 gr/lb.

Air system 11 can be any of a variety of systems suitable for handlingand transporting air for industrial or food processing uses. Forexample, air system 11 can be a configuration of ducts, dampers, fans,blowers, butterfly valves, slide gates, or venturi valves suitable fortransporting and handling air into, out of, or between cooler 7, dryer9, steamer 1, mill 3, or classifier 5. Air system 11 can be configuredto transport air from the cooler 7 and dryer 9 to the mill 3, tovegetable transport system 13 between mill 3 and classifier 5, and/or toclassifier 9. In an embodiment, air system 11 can direct air from cooler7 and/or dryer 9 into and/or through mill 3. In an embodiment, airsystem 11 can direct air from cooler 7 and/or dryer 9 into and/orthrough classifier 5. In an embodiment, air system 11 can direct the airinto and/or through mill 3 and then to classifier 5. In an embodiment,air system 11 can direct the air to a point at or just beyond the exitfrom mill 3, e.g., vegetable transport system 13 just beyond the exitfrom mill 3.

Vegetable transport system 13 can be any of a variety of systemssuitable for handling and transporting vegetable material for industrialor food processing purposes. For example, vegetable transport system 13can be a configuration of chutes, augers, conveyors, elevators, ducts,blowers, suitable for transporting vegetable material (e.g., millablevegetable or vegetable powder) directly or indirectly into, between, orout of steamer 1, mill 3, or classifier 5.

FIG. 3 illustrates another embodiment of the present inventive systemfor milling vegetables. As shown in FIG. 3, the illustrated embodiment,includes steamer 1, mill 3, classifier 5, cooler 7, dryer 9, air system11, vegetable transport system 13, vegetable dryer 19 (e.g., firstvegetable dryer 21 and second vegetable dryer 23), dehuller 15, screen17, vegetable cooler 25, aspirator 29, and cyclone 27. In thisembodiment, steamer 1, mill 3, classifier 5, cooler 7, dryer 9, airsystem 11, and vegetable transport system 13 can be as described withreference to FIG. 2.

In this embodiment, air system 11 can be configured as described withrespect to the embodiment of FIG. 2 and, optionally, to direct air fromthe cooler 7 and/or dryer 9 into or through one or more of the firstvegetable dryer 21, dehuller 15, screen 17, vegetable cooler 25, secondvegetable dryer 23, aspirator 29, cyclone 27, or the like.

In this embodiment, the vegetable transport system 13 can be configuredto transport vegetable material into, through, out of, or between one ormore of the first vegetable dryer 21, dehuller 15, screen 17, vegetablecooler 25, second vegetable dryer 23, aspirator 29, cyclone 27, or thelike. For example, vegetable transport system 13 can be configured totransport vegetable material directly or indirectly from first vegetabledryer 21 to dehuller 15, directly or indirectly from dehuller 15 toscreen 17, directly or indirectly from screen 17 to steamer 1, directlyor indirectly from steamer 1 to vegetable cooler 25, directly orindirectly from vegetable cooler 25 to second vegetable dryer 23,directly or indirectly from second vegetable dryer 23 to aspirator 29,directly or indirectly from aspirator 29 to mill 3, directly orindirectly from mill 3 to classifier 5, and/or directly or indirectlyfrom classifier 5 to cyclone 27.

Vegetable dryer 19 can be can be any of a variety of systems suitablefor drying a millable vegetable. For example, vegetable dryer 19 can bea fluid bed dryer. First vegetable dryer 21 can be configured to receivemillable from, for example, vegetable storage, loading cleaning, orsorting systems. First vegetable dryer 21 can be configured to exposemillable vegetable to a temperature of about 20 to about 120° C., about20 to about 70° C., about 40 to about 60° C., or about 50° C. for about0.25 to about 20 hours, about 1 to about 6 hours, about 2 to about 3hours, or for about 2 hours. Second vegetable dryer 23 can be configuredto receive steamed millable vegetable and to reduce its moisturecontent. For example, second vegetable dryer 23 can be configured todecrease the moisture of the steamed millable vegetable (e.g., soybeans)nibs from about 11 or 12% to about 6% moisture in preparation formilling.

Dehuller 15 can be any of a variety of systems suitable for dehulling avegetable with a hull. For example, dehuller 15 can be a cracking mill.Dehuller 15 can be configured to operate at ambient temperature.

Screen 17 can be any of a variety of systems suitable for screening amillable vegetable, e.g., removing dust from larger portions of thevegetable. For example, screen 17 can be 8 to 12 mesh. Screen 17 can bea commercially available system such as a Kason circular vibrationscreener, Tokuju vibrating screen, Midwestern Industries Gyra-Vibeseparator.

Vegetable cooler 25 can be any of a variety of systems suitable forcooling a millable vegetable. For example, vegetable cooler 25 can be acooling table. Aspirator 29 can be any of a variety of systems suitablefor removing fines and or other lightweight material from a millablevegetable. For example, aspirator 29 can be an air aspirator, such as amultistage air aspirator, such as a 4 stage Kice multiaspirator. Cyclone27 can be any of a variety of suitable apparatus for collecting powder.For example, cyclone 27 can be a standard high efficiency cyclone.

Vegetable Powder Products

The present invention also relates to products made from or includingthe present vegetable powders, e.g., vegetable powders made by thepresent method. Such products include “milk” made from the vegetablepowder. As used herein vegetable milk refers to any aqueous dispersionof the vegetable powder. Such dispersions include suspensions andhomogenates. For example, a milk can be produced from a vegetable powderof a millable vegetable by mixing the powder with hot water, cooking themixture, cooling the milk, and homogenizing the milk.

Additional vegetable powder products include smoothies, butter, creamcheese, sour cream, cheese sauce, cheese, ice cream, yogurt, frozenyogurt, pudding, gelatin, baked goods (e.g., cookies, pancakes, waffles,muffins, breads, tortillas, and the like), or ground meat products(e.g., sausage).

The present invention may be better understood with reference to thefollowing examples. These examples are intended to be representative ofspecific embodiments of the invention, and are not intended as limitingthe scope of the invention.

EXAMPLES Example 1 The Present Invention Produced Advantageously SmallVegetable Powder Particles

This example demonstrated the small particle size achieved for vegetablepowders processed according to the present invention.

Materials and Methods

An embodiment of the present method was employed for processingsoybeans. Briefly: The soybeans were dehulled. Lots A and B of thedehulled beans were steam treated at 105° C. for 4 min. Lot C was notsteamed. The steamed beans were dried. The dried beans were milled to asoy powder. Particle size was evaluated employing an ELZONE® Model 5382Particle Size Analyzer.

Results

Table 1 reports the particle sizes of the soy powder obtained. TABLE 1Vegetable Powder Particle Size Lot A Lot B Lot C Geometric Mean  8.0 μm 8.8 μm  9.6 μm PERCENTILES 0.1% Volume below   2.6 μm  2.6 μm  2.7 μm10% Volume below  3.8 μm  4.7 μm  5.3 μm 50% Volume below  8.2 μm  8.7μm  9.5 μm 70% Volume below 11.7 μm 12.2 μm 12.1 μm 80% Volume below12.4 μm 14.8 μm 13.9 μm 90% Volume below 14.9 μm 18.7 μm 17.3 μm 95%Volume below 17.6 μm 23.9 μm 20.7 μm 99% Volume below 29.7 μm 56.5 μm32.2 μm 99.9% Volume below   66.7 μm 90.2 μm 55.9 μmConclusions

The present method produced a vegetable powder having a particle sizewith advantages such as a mean particle size at or below about 10 μm,with about 90% of the particles of size less than 20 μm.

Example 2 The Present Invention Produces Vegetable Powder WithAdvantageously Low Levels of Lipoxygenase Activity

This example demonstrated the low levels of lipoxygenase activityachieved for vegetable powders processed according to the presentinvention.

Materials and Methods

The dehulled beans (predominantly halves and quarters) were steamtreated temperatures indicated in the table reporting results for 4 min.This brought the beans to 9-16% moisture. The dried beans were milled toa soy powder.

Lipoxygenase activity was determined by a known assay method. Briefly:Steamed beans were milled in a coffee mill and homogenized in distilledwater. The homogenate was allowed to settle at room temperature for 20min. Then the supernatant was decanted and centrifuged for 20 min at1100×g. One mL of this soy extract was diluted with 9 mL of water forthe assay. The lipoxygenase assay was conducted in a 0.2 M phosphatebuffer, pH 9.0, at 30° C. using linoleic acid as substrate and methyleneblue as a reporter. Lipoxygenase activity was followed as the change inoptical density at 660 nm with time at 30° C. (OD/min) using a BeckmanDU-7 spectrophotometer.

Results

Table 2 reports the lipoxygenase activity in the vegetable powderobtained. TABLE 2 Vegetable Powder Lipoxygenase Activity RelativeLipoxygenase Activity Steam Temperature (° C.) (OD/min) No steam heat−0.432 80 −0.421 85 −0.414 90 −0.320 95 −0.185 100  0Conclusions

Embodiments of the present method produced a vegetable powder havingadvantageously low lipoxygenase activity. For example, the methodeliminated lipoxygenase activity by treatment with steam at 100° C.Significant reduction of lipoxygenase activity, which was obtained at100° C., can significantly increase the shelf life of the vegetablepowder.

Example 3 The Present Invention Produces Vegetable Powder WithAdvantageous Protein Dispersibility and Trypsin Inhibitor Activity

This example demonstrated the advantageous levels of proteindispersibility and trypsin inhibitor activity achieved for vegetablepowders processed according to the present invention.

Experiment 1

Materials and Methods

The present method was employed for processing soybeans. The dehulledbeans (predominantly halves and quarters) were steam treated at thetemperatures indicated in the table reporting results for 4 min. Thesteamed beans were dried and the dried beans were milled to a soypowder.

Protein dispersibility index was determined by a known method, AOCSBa10-65. Briefly: The vegetable powder was blended into water to form aslurry. The slurry was centrifuged for 10 min at 2700 rpm. Protein wasdetermined in the supernatant by the Kjeldahl method (AACC 46-16). Theprotein dispersibility index was calculated from the protein levelsaccording to known equations.

Trypsin inhibitor activity was determined by a known method, AOCSBa12-75. Briefly: The beans were ground to at least 100 mesh anddefatted. The ground and defatted beans were extracted with aqueousbase. This extract was diluted with buffer, trypsin was added, and thesample was incubated with substrate. Trypsin activity was measured byhydrolysis of a known substrate (BAPA), which can be followed byabsorbance at 410 nm. The sample was filtered before measuringabsorbance. A reduction in trypsin activity was used to quantify trypsininhibitor activity.

Results

Table 3 reports the protein dispersibility index (PDI) and trypsininhibitor activity (TIU/g) in the soy powder obtained. TABLE 3 SteamTemperature and Resulting Soy Powder Protein Dispersibility Index andTrypsin Inhibitor Activity Protein Dispersibility Trypsin InhibitorActivity Temperature (° C.) Index (%)⁽¹⁾ (TIU/g)⁽²⁾ No heat 91.9 66,378 80 87.4 69,520  85 94.6 72,118  90 89.5 81,102  95 86.6 72,137 100 76.446,143 105 61.7 31,065 110 51.0 20,489 115 40.0 17,749 120 26.5 8,720⁽¹⁾Protein Dispersibility Index, AOCS Ba10-54⁽²⁾Trypsin Inhibitor Activity, on a dry weight basis, AOCS Ba12-75Conclusions

The present method produced soy powder having advantageous levels ofprotein dispersibility and trypsin inhibitor activity. For example,treatment with steam at 105° C. maintains 60% protein dispersibility,while reducing trypsin inhibitor activity by more than 50%. For example,treatment with steam at 110° C. reduced trypsin inhibitor activity byabout 70% to about 20,000 units, while retaining more than 50% proteindispersibility. For example, treatment with steam at 115° C. reducedtrypsin inhibitor activity by about 75% to less than 20,000 units, whileretaining more than 40% protein dispersibility. This method also causessignificant reductions in trypsin inhibitor (e.g., to less than 20,000TIU/g) activity from other beans.

Experiment 2

Materials and Methods

The present method was employed for processing samples of severalvegetables. The raw vegetables (predominantly halves and quarters) weresteam treated at the temperatures indicated in the table reportingresults for 4 min. The dried beans were milled to a vegetable powder.Protein dispersibility index and trypsin inhibitor activity weredetermined by known methods as described above.

Results

Table 4 reports the protein dispersibility index (PDI) and trypsininhibitor activity (TIU/g) in the raw vegetables, raw pea powder, andsteam treated vegetable powders. TABLE 4 Protein Dispersibility Indexand Trypsin Inhibitor Activity for Raw Vegetables and Treated VegetablePowders Trypsin Protein Dispersibility Inhibitor Activity VegetableSample Index (%)⁽⁵⁾ (TIU/g)⁽⁶⁾ Raw Yellow Peas 73.2 2,900 Raw Yellow PeaPowder 79.2 2,200 Treated Yellow Pea Powder⁽¹⁾ 63.4 <2,000 Raw PintoBeans 83.1 15,300 Treated Pinto Bean Powder⁽²⁾ 35.7 <2,000 Raw BlackBeans 79.3 17,000 Treated Black Bean Powder⁽³⁾ 51.7 <2,000 Raw Soybeans90.3 53,300 Treated Soybean Powder⁽⁴⁾ 66.6 27,200⁽¹⁾Steam Heat at 105° C. for 4 min.⁽²⁾Steam Heat at 115° C. for 4 min.⁽³⁾Steam Heat at 115° C. for 4 min.⁽⁴⁾Steam Heat at 105° C. for 4 min.⁽⁵⁾Protein Dispersibility Index, AOCS Ba10-54⁽⁶⁾Trypsin Inhibitor Activity as is basis, AOCS Ba12-75Conclusions

The present method produced vegetable powders having advantageous levelsof protein dispersibility and trypsin inhibitor activity. For example,steam treatment retains more than about 70% of the proteindispersibility found in the raw vegetable. For example, treatment withsteam at 105° C. reduced trypsin inhibitor activity to about only 50% ofthat found in the raw vegetable, and in each case to less than about20,000 TIU/g.

Experiment 3

Experiment 3a—Soy Powder

The present method was employed for processing four thousand pounds ofsoybeans. The soybeans were received with a moisture content of 9.3%.They were dried at 50° C. to 6.7% moisture, cracked, and dehulled. Thedehulled beans (predominantly halves and quarters) were steam treated at115° C. for 4 min. This brought the beans to 13.3% moisture. The steamedbeans were dried for approximately 4 hr at 70° C. This brought the beansto 4.4% moisture. The dried beans were milled to a soy powder with anaverage particle size of

This soy powder has a 46.6% PDI and trypsin inhibitor level of 12,800TIU/G.

Experiment 3b—Soy Powder

The present method was employed for processing four thousand pounds ofsoybeans. The soybeans were received with a moisture content of 9.3%.They were dried at 50° C. to 5.8% moisture, cracked, and dehulled. Thedehulled beans (predominantly halves and quarters) were steam treated at107° C. for 4 min. This brought the beans to 12.1% moisture. The steamedbeans were dried for approximately 4 hr at 70° C. This brought the beansto 5.9 % moisture. The dried beans were milled to a soy powder with anaverage particle size of 10 μm.

This soy powder has a 66.1% PDI and trypsin inhibitor level of 20,800TIU/G.

Experiment 3c—Black Bean Powder

The present method was employed for processing one thousand pounds ofblack beans. The black beans were received with a moisture content of13.4%. They were dried at 50° C. to 10.5% moisture, cracked, anddehulled. The dehulled beans (predominantly halves and quarters) weresteam treated at 115° C. for 4 min. This brought the beans to 15.3%moisture. The steamed beans were dried for approximately 3 hr at 70° C.This brought the beans to 5.2.% moisture. The dried beans were milled toa black bean powder with an average particle size of 10 μm.

This black bean powder has a 51.7% PDI and trypsin inhibitor level of<2,000 TIU/G.

Experiment 3d—Black Bean Powder

The present method was employed for processing one thousand pounds ofblack beans. The black beans were received with a moisture content of14.0%. The beans were steam treated at 115° C. for 8 min. This broughtthe beans to 20.7% moisture. The steamed beans were dried forapproximately 3 hr at 70° C. This brought the beans to 6.4% moisture.The dried beans were milled to a black bean powder with an averageparticle size of 10 μm.

This black bean powder has a 57.6% PDI and trypsin inhibitor level of<2,000 TIU/G.

Experiment 3e—Pinto Bean Powder

The present method was employed for processing one thousand pounds ofpinto beans. The pinto beans were received with a moisture content of15.6% and dehulled. The dehulled beans were steam treated at 115° C. for4 min. This brought the beans to 19.2% moisture. The steamed beans weredried for approximately 4 hr at 70° C. This brought the beans to 4.1%moisture. The dried beans were milled to a pinto bean powder with anaverage particle size of 10 μm.

This pinto bean powder has a 35.7% PDI and trypsin inhibitor level of<2,000 TIU/G.

Conclusions

The present method produced vegetable powders having advantageous levelsof protein dispersibility and trypsin inhibitor activity.

Example 4 The Present Invention Produces Vegetable Powder WithAdvantageous Fresh and Pleasant Flavor

This example demonstrated the advantageous fresh and pleasant flavor andpleasing color achieved for vegetable powders processed according to thepresent invention.

Materials and Methods

The present method was employed for processing soy beans. The dehulledbeans were steam treated temperatures indicated in the table reportingresults for about 4 min. The dried beans were milled to a vegetablepowder.

The soy powders were processed to make soymilk to evaluate theirorganoleptic characteristics. Soy powder (70 g) was blended into 1000 mLof hot water (82° C.) for 2 min, cooked to boiling for 2 min, and thenfiltered to get rid of large insoluble residues. The cooked soymilk wascooled immediately to room temperature. After cooling, the soymilk washomogenized at 8000 psi to produce a smooth texture, and evaluated forcolor and flavor.

Flavor and color were evaluated by known methods. Briefly, the testingincluded organoleptic evaluation by a three member panel trained andexperienced with soymilk.

Results

Table 5 reports the results of evaluation of flavor, color, and offtaste achieved by employing in soymilk a vegetable powder made by thepresent method. TABLE 5 Soymilk Flavor, Color and Off Flavor Improved bySteam Treatment According to the Present Invention. Steam Temperature (°C.) Flavor¹ Color² Off Taste³ 107 8.5 9 1 95 5 5 5¹A score of 10 the best, fresh and pleasant, 1 is the lowest with greenbeany flavor²A score of 10 is the best creamy yellow to white, 1 is the lowest pinkto dark brown³A score of 10 has the highest off flavor and rancidity while 1 is thelowest off flavor with no rancidityConclusions

The present method produced vegetable powders that produce milks havingadvantageous good flavor, good color, and lack of off flavor. Forexample, the present steam treatment increased the flavor rating by 3.5points, which indicates reduction in green and beany off flavors. Forexample, the present steam treatment decreased the off taste rating by 4points, which indicates elimination of rancid (e.g., soapy and painty)off-flavors.

It should be noted that, as used in this specification and the appendedclaims, the singular forms “a,” “an,” and “the” include plural referentsunless the content clearly dictates otherwise. Thus, for example,reference to a composition containing “a compound” includes a mixture oftwo or more compounds. It should also be noted that the term “or” isgenerally employed in its sense including “and/or” unless the contentclearly dictates otherwise.

It should also be noted that, as used in this specification and theappended claims, the phrase “adapted and configured” describes a system,apparatus, or other structure that is constructed or configured toperform a particular task or adopt a particular configuration to. Thephrase “adapted and configured” can be used interchangeably with othersimilar phrases such as arranged and configured, constructed andarranged, adapted, constructed, manufactured and arranged, and the like.

All publications and patent applications in this specification areindicative of the level of ordinary skill in the art to which thisinvention pertains.

The invention has been described with reference to various specific andpreferred embodiments and techniques. However, it should be understoodthat many variations and modifications may be made while remainingwithin the spirit and scope of the invention.

1. A method of producing vegetable powder, comprising: contactingmillable vegetable with steam at about 95° C. to about 130° C. for about3 to about 12 min; milling the millable vegetable, milling comprising:contacting the vegetable with air previously passed through a coolingapparatus during milling, contacting the vegetable with air previouslypassed through a drying apparatus during milling, or contacting thevegetable during milling with air previously passed through a coolingapparatus and a drying apparatus; simultaneously with milling,classifying the milled vegetable, classifying comprising: contacting thevegetable with air previously passed through a cooling apparatus duringclassifying, contacting the vegetable with air from a drying apparatusduring classifying, or contacting the vegetable during classifying withair previously passed through a cooling apparatus and a dryingapparatus; and producing vegetable powder of which 70% has a particlesize less than 20 microns.
 2. The method of claim 1, wherein themillable vegetable comprises a hull; and the method further comprises:dehulling the millable vegetable, dehulling comprising: dehullingvegetable having a mixture of sizes; gently drying the vegetable anddehulling the gently dried vegetable; dehulling at ambient temperature;or a combination thereof.
 3. The method of claim 1, comprisingcontacting millable vegetable with steam at about 105° C. to about 120°C.
 4. The method of claim 1, comprising contacting millable vegetablewith steam for about 4 min to about 8 min.
 5. The method of claim 1,wherein the air previously passed through a cooling apparatus comprisesair at temperature of about 20° F to about 60° F.
 6. The method of claim1, wherein the millable vegetable comprises legume, grain, or mixturethereof.
 7. The method of claim 6, wherein the millable vegetablecomprises legume seed, grain seed, or mixture thereof.
 8. The method ofclaim 6, wherein the legume comprises black bean, pinto bean, red bean,broad bean, lentil, soybean, pea, or mixture thereof.
 9. The method ofclaim 6, wherein the legume comprises whole legume, legume germ, legumecotyledon, or mixture thereof.
 10. The method of claim 1, wherein thevegetable comprises soybean.
 11. The method of claim 1, wherein 80% ofthe vegetable powder has a particle size of less than about 20 μm.
 12. Apowder of a millable vegetable, wherein: aqueous homogenate of thepowder has flavor rank of at least about 7, indicating flavor ofslightly beany flavor and little nutty flavor; the flavor rank based onflavor scale on which 1 is the lowest rank and indicates green beanyflavor and 10 is the highest rank and indicates fresh and pleasantflavor.
 13. The vegetable powder of claim 12, wherein the aqueoushomogenate of the powder has flavor rank of 8, indicating good, nutty,clean soymilk flavor.
 14. The vegetable powder of claim 12, wherein theaqueous homogenate of the powder has off taste rank of less than orequal to about 3, indicating off taste of slightly oxidized, slightcardboard, or somewhat green off taste; the off taste rank based on offtaste scale on which 1 indicates the lowest amount of off taste and norancid taste and 10 indicates the highest amount of off taste andmaximum rancidity.
 15. The vegetable powder of claim 14, wherein theaqueous homogenate of the powder has off taste rank of
 1. 16. Thevegetable powder of claim 12, wherein 80% of the particles of thevegetable powder have particle size of less than about 20 μm.
 17. Thevegetable powder of claim 12, wherein the millable vegetable compriseslegume, grain, or mixture thereof.
 18. The vegetable powder of claim 17,wherein the millable vegetable comprises legume seed, grain seed, ormixture thereof.
 19. A food product comprising as an ingredient powderof millable vegetable, wherein: aqueous homogenate of the powder hasflavor rank of at least about 7, indicating flavor of slightly beanyflavor and little nutty flavor; the flavor rank based on flavor scale onwhich 1 is the lowest rank and indicates green beany flavor and 10 isthe highest rank and indicates fresh and pleasant flavor.
 20. A systemfor producing vegetable powder comprising: steaming apparatus, millingapparatus, classifying apparatus, vegetable handling apparatus, aircooling apparatus, air drying apparatus, and air handling apparatus; thevegetable handling apparatus configured to transport the vegetable fromthe steaming apparatus to the milling apparatus and from the millingapparatus to the classifying apparatus; the air handling apparatusconfigured to transport the air from the cooling apparatus and dryingapparatus to the milling apparatus, to the vegetable handling apparatusbetween the milling apparatus and the classifying apparatus, and to theclassifying apparatus.